This invention relates to an improved refrigeration system embodying an integral coolant fluid check valve and having a reduced number of coolant fluid tubing connections.
An example of a conventional refrigeration system is shown in FIG. 1, and includes a vertically oriented rotary compressor 1 mounted in a closed shell 1a for supplying compressed gaseous refrigerant fluid to a condenser 10 through an output line 11. To complete the system the refrigerant fluid flows serially, in conventional manner, through an expansion device 9 such as a capillary tube or valve, an evaporator 8, an accumulator 6 for separating the liquid and gaseous components of the refrigerant fluid and retaining the former, and a vertically oriented check or non-return valve 4a schematically represented by an arrow. The check valve is flanked by individual pipe sections 4 either integral with or sealingly joined thereto, and the individual connections of the accumulator 6 and check valve 4a between the evaporator and the suction intake elbow 2 of the compressor are completed by tubing sections 3a, 3b and 3c as shown. The respective connections between the ends of such tubing sections and the suction intake elbow, check valve and accumulator are made by brazing to ensure fluid tightness.
There are thus a total of five such brazing connections at tubing joints a, b, c, d and e in a conventional installation, and each of this multiplicity of brazed joints represents a potential source of rupture and refrigerant fluid leakage due to fatigue cracks or the like attendant to operational vibrations after prolonged usage.
The installation of the check valve 4a downstream of the accumulator 6 as shown in FIG. 1 is preferred in systems having a large refrigerant capacity to minimize "reverse stream" vibrations and collision noise or "pipe rattle" during compressor start-up. The reversal of the respective check valve and accumulator dispositions is also conventional, however, in systems where the introduction of condensed liquid refrigerant and entrained lubricating oil into the compressor suction intake, and the attendant locking of the compressor during start-up, is a more dominant problem/consideration. In either alternative a total of five brazed tubing section joints is still involved.